The present invention relates to paper-like sheet discriminators.
In an apparatus for handling paper money such as, for example, automatic teller machine (ATM) or vending machine, discrimination of genuineness/spuriousness of paper money is important and therefore, the apparatus incorporates a paper-like sheet discriminator in the form of a paper money discriminator.
As a conventional paper money discriminator for discriminating the genuineness/spuriousness of paper money, an apparatus described in, for example, JP-A-63-247895 has been known.
In the paper money discriminator described in the gazette, paper money is inserted between a reference roller and one end of a detection lever, a displacement of the lever is detected with a displacement detection means provided at the other end of the detection lever and the genuineness/spuriousness is discriminated in accordance with the number of depressions and raised portions in the detected displacement signal to exclude spurious paper money prepared with color printer, color copier or the like.
In the apparatus described in the aforementioned JP-A-63-247895, a thickness of paper money is detected to deliver a detection signal and the number of depressions and raised portions is detected from the detection signal to discriminate the genuineness/spuriousness.
Some spurious paper money is, however, skillfully spurious paper money having unevenness intentionally formed on a printing surface or paper sheet and such a spurious paper money sheet is difficult to discriminate from genuine paper and is therefore possibly overlooked with the conventional paper money discriminator.
In addition, there is also a possibility that erroneous detection happens in which delicate crumples formed in paper money are recognized as depressions/raised portions and even genuine paper is determined to be spurious paper.